package xyf.p10.dp;

/**
 * ClassName: P0070_ClimbStairs
 * Description:
 * Author: xyf
 * Date: 9/9/22 10:28 AM
 * Version: 1.0
 **/
public class P0070_ClimbStairs
{
    public int climbStairs(int n)
    {
        if (n == 1)
        {
            return 1;
        }

        if (n == 2)
        {
            return 2;
        }

        return climbStairs(n - 1) + climbStairs(n - 2);
    }

    public int climbStairs1(int n)
    {
        if (n == 1)
        {
            return 1;
        }

        if (n == 2)
        {
            return 2;
        }

        int[] dp = new int[n];
        dp[0] = 1;
        dp[1] = 2;
        for (int i = 2; i < n; i++)
        {
            dp[i] = dp[i - 1] + dp[i - 2];
        }
        return dp[n - 1];
    }
}